Pneumatically operated log carriage and controls therefor



Jlme 1955 1 s. SUNDLOF PNEUMATICALLY OPERATED LOG CARRIAGE AND CONTROLSTHEREFOR 7 Sheets-Sheet 1 Filed Jan. so, 1953 June 21,1955 G.SUNDLC) F 1,1 2,711,198

PNEUMATICALLY OPERATED LOG CARRIAGE I AND CONTROLS THEREFOR Filed Jan.50. 1955 7 Sheets-Sheet 2 June 21, 1955 G SUNDLOF 2,711,198

PNEUMATICALL? OPERATED LOG CARRIAGE AND CONTROLS THEREFOR Filed Jan. 50,1953 7 Sheets-Sheet 3 June 21, 1955 G SUNDLOF 2,711,198,

PNEUMATICALLY OPERATED LOG CARRIAGE AND CONTROLS THEREFOR Filed Jan. 30,1955 7 Sheets-Sheet 4 June 21, 1955 s b 2,711,198

PNEUMATICALLY OPERATED LOG CARRIAGE AND CONTROLS THEREFOR Filed Jan. 50,1953 7 Sheets-Sheet 5 June 21, 1955 .=v 2,711,198

- PNEUMATICALLY OPERATED LOG CARRIAGE AND CONTROLS THEREFOR Filed Jan.50, 1953 I She e-ts-Sheet s June 21, 1955 U D Q 7 2,711,198

PNEUMATICALLY OPERATED LOG CARRIAGE AND CONTROLS THEREFOR Filed Jan. 50,1955 7 Sheets-Sheet 7 United States Patent 0 PNEUMATICALLY OPERATED LOGCARRIAGE AND CONTROLS THEREFOR Gustav Sundltif, Soderhamn, Sweden,assignor to Soderllamns Verkstader Alrtiebolag, Soderharnn, SwedenApplication January 30, 1953, Serial No. 334,298 laims priority,application Sweden February 5, 1952 8 Claims. (Cl. 143-118) The presentinvention relates to improvements in i'luid pressure operated apparatusof the type including a plurality of servo-motors for transmittingpower.

More particularly this invention relates to an improved pneumaticallyactuated log carriage and to the controls therefor.

The invention the type used in connection with frame saws, particularlyfor feeding logs into frame saws. Log carriages of this type include loggripping means comprising jaws or claws that are movable toward and awayfrom one another to hold a log on the carriage, mechanism for turningthe gripping means about an axis parallel to the direction of movementof the carriage and mechanism for shifting the gripping means laterally.

Accordingly the present invention has for a particular object theprovision of improved fluid pressure actuated means for gripping a log,turning the gripping means and side or laterally shifting the same.

A further object includes the provision of a log carriage of theaforementioned type in which a rapid and exact setting of the grippingmeans or claw unit is attained with respect to its angle of rotation andthe distance of lateral movement.

More particularly and in connection with the aforementioned object, theinvention aims to provide an improved control for the log carriageoperative to fix the gripping means or claw unit in the proper orcorrect position so as to ensure a straight sawing of the log therebypreventing a change in the position of rotation or turning of the clawunit which change would result a in a helical saw cut and furtherpreventing a change in the lateral position of the unit, and whichlatter change would result in a curved saw cut.

It is a further object of the invention tov provide pneumaticallyoperated means for both setting the claw unit and for fixing the sameand a control mechanism therefor operative to effect the fixing of theunit at the moment the setting thereof is completed.

It is an additional object of this invention to provide a centralizedcontrol arrangement for the claw unit and the means for setting andfixing the same.

Further and more specific objects will be apparent from the followingdescription taken in connection with the accompanying drawingsillustrating a preferred embodiment and in which:

Figure 1 is a side elevational view of the improved log carriage,

Figure 2 is a top plan view of the log carriage shown in Figure 1,

Figure 3 is an end elevational view as viewed from the light in Figure1,

Figure 4 is a similar view as seen from the left in Figure 1,

Figure 5 is a fragmentary view on an enlarged scale and partly invertical section and illustrating the means for supporting and operatingthe claw means,

Figure 6 is a fragmentary view partly in section illusfurther relates toa log carriage of I 'ice trating the claw means as viewed from the frontthereof, Figure 7 is a fragmentary view partly in elevation and partlyin cross section and illustrating some of the pneumatically operatedmeans, i Figure 8 is a fragmentary end elevational view illustratingsome of the structure shown in Figure 7 as viewed from the right,

Figure 9 is a fragmentary view partly in elevation and partly inhorizontal cross section and illustrating'the means for shifting theclaw unit laterally, and

Figure 10 is a similar view illustrating the means for shifting the clawunit laterally in vertical cross section.

in the drawings, the reference numeral 1 indicates the frame of the logcarriage, said frame mounting wheels 2 running on rails 2'. The logcarriage frame further mounts chain wheels 2" which are in mesh withopposite moving haulage chains, not shown. Control means forming no partof this invention selectively lock one or the other of chain wheels 2"so that the haulage chains can selectively move the carriage towards oraway from a saw frame, not shown. On therear part of the frame anoperators seat 3 is securely mounted. Between and securely mounted inthe side .sections of the frame extends transverse shaft 4. On thecentral portion of the shaft 4 is provided a piston head 5, Figs. 5

and 10, either attached to the shaft .or constituting an 7 integral partof the same. The piston head 5 is enclosed in a cylinder 6. The cylinder6 constitutes the supporting structure of a cross-frame which ismovablealong the shaft 4 and which includes the plates 7 formed on theends of said cylinder, brackets 8 securely mounted on said plates forsupporting the claw unit or gripping mechanism of the log carriage andoperating means for said gripping means, a beam 9, Figs. 1, 2 and 5,together with a bail-shaped member 9' for supporting the log, and abrake plate 69 cast in one piece with the cylinder 6. In parallel Withthe cylinder 6 extends a smaller cylinder 16, Figs. 5 and 9, which issecurely mounted on the cylinder 6 and encloses a piston 11 having apiston rod 12 extending through the cylinder and having its endsattached to the side sections of the frame 1.

On the intermediate portion of a transverse beam 13 of the frame'l,Figs. 1, 5 and 9, a cylinder 14 issecurely mounted. This cylinder 14extends at right angles to the cylinder 6 and is open towards the same.The cylinder 14 encloses a piston 15 which extends approximately to theoutside of the cylinder 6, viz. to the brake plate 60, and for brakingpurpose is forced towards the cylinder 6 by means of air under pressuresupplied through the conduit 16 connected to the cylinder 14. Thecylinder 6 has its opposite ends connected to conduits 17 and 18 for thesupply and exhaust of air under pressure whereby the cylinder 6 may bemoved along the shaft 4 in either direction thereby moving the claw unitlaterally. The conduits 16, 17 and 2.8 are connected to a three-wayvalve 20, Figs. l4, for communication with the airpressure distributingchamber 19, said valve having a handle 21 for controlling said conduitsas will be described later.

The cylinder 10, Fig. 9, together with the associated piston 11constitutes a dashpot device for damping the movement of the cylinder 6.To this effect the cylinder 10 is provided with a conduit 22 extending,from one end of said cylinder to the other, the spaces enclosed by saidconduit and the spaces within the cylinder on opposite sides of thepiston 11 being filled with oil. The conduit 22 includes a valve 23 forcontrolling the flow of oil and thereby regulating the damping effect sothat the speed of the lateral or shifting movement canbe adjusted.

In the vertical brackets 8 of the cross-frame including the cylinder 6as supporting structure, a transverse shaft 24, Figs. 1 and S, issupported. On said shaft 24 is rockably mounted a cylinder 25 havingtherein a piston 26 which is provided with a portion protruding from therear open 'end of the cylinder 25, facing the drivers seat 5. Theportion of the piston protruding from the cylinder is hollow and housesa combined thrust and radial bearing 27 for a longitudinal shaft 28constituting the control shaft for operating the claws 29 of the logcarriage. The said shaft 28 is rotatable in the hollow piston 26 butheld against longitudinal movement in the same. The end of the piston 26supports a cover for protecting the bearing 27. The shaft 28 is guidedin a sleeve 39 provided within the cylinder 25 and constituting a partor sleeve of the same. Said cylinder part 30 has a forwardly projectingextension 31 constituting a bearing housing for rotatably mounting aclaw bracket 32. The claw bracket 32 is provided with pivots 33 on whichare mounted gripping claws or dogs 29. The claws are formed as hellcrank levers and include suitable gripping surfaces on their front armsand pins 34 in the rear arms. The pins 34 engaging in radially extendingslots 35 that are provided in a head 36 formed on the shaft 28.

To the two opposite ends of the cylinder 25 are connected two conduits37, 38, which extend from the valve '39, Fig. 2, communicating with theair-pressure chamber 19 and provided with a handle By means of saidvalve 39 either end of the piston 25 can be subjected to the pressure ofthe air in said chamber for moving the piston 26 and thereby the shaft28 longitudinally in either direction, so that the claws 29 can be movedtogether or apart.

The cross-frame movable along the transverse shaft 4 as described,supports the casing 41 of a pneumatic motor, Fig. 5, and which casing isattached to the frame by any suitable means. This motor is of the rotaryreversible type well-known in the art, and the shaft of of the sameimparts rotation or turning movement to the claw unit by means of agearing 42 including an internal gear operatively connected with apinion 43 meshing with a gear 44 attached to the claw bracket 32.

The external circumferential surface of the external gear'of'the gearing42 is engaged by two brake levers 45, Fig. 6, which are pivoted on rods46 securely mounted in the cross-frame. Between the downwardly extendingarms 47 of the brake levers is a brake motor, comprising a cylinder 48connected with one arm 47, and a piston 49 connected with the other arm47. Moreover, the arms 47 are interconnected by means of a tensionspring 5% holding the brake levers out of engagement with said gear 42when no braking shall occur. The 'pneumatic'motor 41 is connected to theair-pressure chamber 19 through a conduit 51 permanently open towardssaid chamber. The supply of air to the motor is controlled by thegovernor valve 52, Fig. 3. The valve 52 is operated from the handle 53by means of a link 54, see also Figs. 2, 7 and 8. The same handle 53operates also, through the link 55, a valve 56 for controlling theconduit 57 supplying air under pressure from the chamber 19 to the brakecylinder 43.

The air pressure or distributing chamber 19 distributes air underpressure to the conduit arrangements including the conduits 37, 38feeding the pneumatic motors 25, 26, the conduit 51 feeding thepneumatic motor 41, and the conduits 17 and 18 feeding the pneumaticmotors 5 and 6. Additionally air under pressure passes from thedistributing chamber through conduits 15 and 16 feeding the associatedpneumatic brake means 48, 49 and 14, 15 respectively. The distributingchamber is supplied with 'air under pressure through conduit 79, Figures1 and 3, which receives air under pressure from a stationary cornpressor76 shown diagrammatically in Figure 4. A flexible hose 74 communicateswith the stationary pipe-line 75 fed by the compressor, and feeds air toconduit 71 which communicates with the interior of the pole '71) via avalve 73 and a short conduit 70. An additional short conduitcommunicates at one end with the pole 72 and at its other end with avalve 81 which in turn communicates with an outlet conduit 77. Theoutlet conduit 77 is for supplying air to pneumatic motors of separatestationary mechanisms, not shown. Thus, for instance,

this outlet conduit supplies air for the motor of the feedwork of theframe saw or supplies air to the motor for the log kicker fortransferring the logs onto bail 9' over the feed member 9".

By means of the equipment described above the operator while remainingon his seat 3 can control the following three functions pneumatically bysimple ma nipulations:

(1) Operating the claws for gripping and clamping a log resting upon thebail 9;

(2) Rotating the claw unit together with the log as clamped to aposition of rotation 01' a setting position suitable for feeding the loginto the frame saw and simultaneously fixing or locking the setting;

(3) Moving the cross-frame transversely together with claw unit and logto a lateral or setting position suitable for feeding the log into theframe saw and simultaneously fixing or looking the setting.

in this specification the expression forward is used for a movementtowards the claws and the expression backward is used for a movementtowards the seat of the operator or driver. In similar way theexpression front and rear are used.

Gripping operation For gripping the logs with the claws the driver hasto turn the handle 40, for instance towards the right hand side of thecarriage in Fig. 2. Then, air under pressure will flow from the chamber19 through the valve 39 and the conduit 37 to the front end of thecylinder 25, moving the piston 26 together with the shaft 2S backwards.Thereby, the claws 29 are moved together, firmly clamping the log L.This firm grip is maintained as long as the air-pressure is acting uponthe piston. When the handle 40 was operated towards the right-hand side,a connection from the rear end of the.

moved for For rotating the claw unit together with the log clampedbetween the claws the driver has to turn the handle 53, for instancetowards the right-hand side. Thereby, the link 54 is lowered and thelink 53 is raised, The first-mentioned link opens the valve 52 forstarting the pneumatic motor 41 for clockwise rotation and thelastmentioned link operates the brake valve 55 to a position fordischarging air under pressure from the brake cylinder 48 through theconduit 57 to the atmosphere.

Now, the motor 41 is allowed to operate until the claw unit by the aidof the gearing comprising the gear ring 44 has reached the desiredposition of rotation. Then, the handle 53 is operated in the oppositedirection for closing the valve 52 and simultaneously supplying airunder pressure to the brake cylinder 48.

Lateral movement of ct'mv unit For moving the claw unit laterally theframe is moved along the transversal shaft ing the cylinder 6. Forperforming handle 21 is turned, for instance tows side. Then, air underpressure from the 0 will flow through the valve ZGand the conduit 13 tothe Thereby, the air under pressure is caused Thus, I

right-hand side of the cylinder 6. As the piston is immovable, thecylinder 6 together with the cross-frame and the means for gripping androtating the claw unit as well as the log will move towards theright-hand side as long as the air under pressure is supplied to thecylinder. 5

At. the same time as the handle 21 is moved from its central position toeither side, the valve 20 opens a connection from the cylinder 14through the conduit 16 to the atmosphere, whereby the brake normallylocking the cylinder 6 in the position as set is released. When thelateral movement of the cross-frame to the desired position has beencompleted, the handle 21 is again moved back to the central position,whereby the supply of air under pressure to the cylinder 6 throughconduit 18 is out 01f, air under pressure now being supplied through theconduit 16 to the brake cylinder 14 for locking the cylinder 6 in thenew lateral position as set.

For laterally moving the cross-frame towards thelefthand side the handle21 is operated towards the lefthand side, air under pressure now beingsupplied through 2 the valve and the conduit 17 to the left-hand side ofthe cylinder 6.

Because the air is somewhat elastic and expansible th lateral movementwould progress unequally if the damping means 10, 11, 22, 23 were notprovided. Now, when the cylinder 6 together with the cross-frame ismoved laterally, for instance towards the right-hand side, the

oil present in the cylinder space'on the left of the piston 11 in Fig.9, will flow through the conduit 22 and the valve 23 to the cylinderspace on the right of the piston 11. When the cylinder 6 is movedtowards the left-hand side, the oil will of course flow in the oppositedirection.

The velocity of the lateral movement of the cross-frame is dependentupon the section of the passage in the valve 23 and also upon theviscosity of the oil used.

I claim:

l. A log carriage comprising in combination, a mobile base frame, anoperators seat on said base frame, a cross frame on said base frame andmeans mounting the cross frame for lateral shifting movement relative tothe base frame, a cylindrical bearing housing carried by the cross frameand having its axis extending longitudinally of the base frame, abracket means rotatably mounted in said bearing housing, log grippingclaw means supported in said bracket and including individual claws,means mally fixing the same, a third pneumatically operatedmechanism forlaterally shifting the cross frame and thereby moving the clawslaterally as a unit, said third pneumatically operated mechanismcomprising a cylinder and a piston, said cylinder supporting the crossframe and constituting a base portion of the same, a rod ex-, tendingtransversely of and supported in the base frame 6 and extending throughsaid cylinder, said piston being embodied with said rod centrallythereof, a pneumatically actuated brake mechanism operably associatedwith said third mentioned pneumatically operated mechanism for, normallyfixing the same, control means common to said second mentionedpneumatically operated mechanism and the pneumatically actuated brakemeans associated therewith for selectively and simultaneously actuatingsaid pneumatically operated mechanism and disengaging,

the associated brake means for turning the claw unit to set the same andsimulaneously stopping said second mentioned pneumatically operatedmechanism and engaging the brake mechanism for fixing the position ofthe claw unit, control means common to said third mentionedpneumatically operated mechanism and the pneumatically actuated brakemeans associated therewith for selectively and simultaneouslyactuating'said pneumatically operated mechanism and disengaging thebrake means associated therewith for effecting lateral shifting movementof the unit and stopping the actuation of said third mentionedpneumatically operated mechanism and engaging the associated brake unitfor fixing the claw unit in its adjusted position and means mounting thecontrol means in accessible positions in front of the operators seat.

2. A log carriage comprising in combination, a mobile base frame, across frame on said base frame and means mounting the cross frame forlateral shifting movement relative to the base frame, a cylindricalbearing housing carried by the cross frame'and having its axis extendinglongitudinally of the base frame, a bracket means rotatably mounted insaid bearing housing, log gripping claw means supported in said bracketmeans and including individual claws, means mounting the individualclaws for movement toward and away from each other, said first mentionedpneumatically operated mechanism comprising a cylinder, a piston movabletherein, a sleeve attached centrally of said cylindrical bearing housingand constituting an extension of the same, the said cylinder beingmounted concentrically around said sleeve and supported by said housing,the said piston being cylindrical and slidable between said sleeve andsaid cylinder, a centrally disposed piston rod connected with saidpiston and guidedin said sleeve and said bracket means for operating theclaws, a first pneumatically operated mechanism on the cross frame formoving the claws toward and away from one another, a secondpneumatically operated mechanism on the base frame for imparting rotarymovement to said bracket means and thereby turning the claws as a unit,a pneumatically actuated brake mechanism operably associated with saidsecond mentioned pneumatically operated mechanism for normally fixingthe same, a third pneumatically operated mechanism for laterallyshifting the cross frame and thereby moving the'claws laterally as aunit, said third pneumatically operated mechanism comprising a cylinderand a piston, said cylinder supporting the cross frame and constitutinga base portion of the same, a rod extending transversely of andsupported in the base frame and extending through said cylinder, saidpistonbeing embodied with said rod centrally thereof, a pneumaticallyactuated brake mechanism operably associated with said third mentionedpneumatically operated mechanism for normally fixing the same, controlmeans common to said second mentioned pneumatically operated mechanismand the pneumatically actuated brake means associated therewith forselectively and simultaneously actuating said pneumatically operatedmechanism and disengaging the associated brake means for turning theclaw unit to set the same and simultaneously stopping said secondmentioned pneumatically operated mechanism and engaging the brakemechanism for fixing the position of the claw unit, and control meanscommon to said third mentioned pneumatically operated brake meansassociated there- 0 with for selectively and simultaneously actuatingsaid pneumatically operated mechanism and disengaging the brake meansassociated therewith for effecting lateral shifting movement of the unitand stopping the actuation of said third mentioned pneumaticallyoperated mechanism and engaging the associated brake unit for fixin theclaw unit in its adjusted position.

'3. A'log carriage comprising in combination, a mobile base frame, across frame on said base frame and means mounting the cross frame forlateral shifting movement relative to the base frame, a cylindricalbearing housing carried bythe cross frame and having its axis extendinglongitudinally of the base frame, a bracket mea'ns rotatably mounted insaid bearing housing, log gripping claw means supported in said bracketmeans and including individual claws, means mounting the individualclawsfor movement toward and away from each other, a first pneumaticallyoperated mechanism on the cross frame for moving the claws toward andaway from one another, a second pneumatically operated mechanism on thebase frame for imparting rotary movement to said bracket 7 means andthereby turning the claws as a unit, a pneumatically actuated brakemechanism operably associated with said second mentioned pneumaticallyoperated mechanism for normally fixing the same, an additional rodextending transversely of and supported in the base frame in parallelismwith the piston rod of thesecond mentioned pneumatically operatedmechanism, a piston securely mounted on said additional rod centrallythereof,

an auxiliary cylinder supported by the cylinder of the lateral movementof the cross frame in accordance with the setting of the regulatingvalve, a third pneumatically operated mechanism for laterally shiftingthe cross frame and thereby moving the claws laterally as a unit, saidthird pneumatically operated mechanism comprising a cylinder and apiston, said cylinder supporting the cross frame and constituting a baseportion of the same, a rod extending transversely of and supported inthe base frame and extending through said cylinder, said piston beingembodied with said rod centrally thereof, a pneumatically actuated brakemechanism operably associated with said third mentioned pneumaticallyoperated mechanism for normally fixing the same, control means common tosaid second mentioned pneumatically operated mechanism and thepneumatically actuated brake means associated therewith for selectivelyand simultaneously actuating said pneumatically operated mechanism anddisengaging the associated brake means for turning the claw unit to setthe same and simultaneously stopping said second mentioned pneumaticallyoperated mechanismand engaging the brake mechanism for fixing theposition of the claw unit, control means common to said third mentionedpneumatically operated mechanism and the pneumatically operated brakemeans associated therewith for selectively and simultaneously actuatingsaid pneumatically operated mechanism and disengaging the brake rneansassociated therewith for effecting lateral shifting movement of the unitand stopping the actuation of said third mentioned pneumaticallyoperated mechanism and engaging the associated brake unit for fixing theclaw unit in its adjusted position.

4. A log carriage as defined in and by claim 1, including a brake plateintegral with the cylinder of the third mentioned pneumatically operatedmechanism and the second mentioned pneumatically actuated brakemechanism comprising a brake cylinder supported by the base rame andextending at right angles to the cylinder of the third mentionedpneumatically operated mechanism and a piston slidably mounted in thebrake cylinder and including an end projecting from said rake cylinderfor engagement with said brake plate.

5. A log carriage as claimed in claim 1, and further including a tubularconduit carried by the base frame and adapted to be placed incommunication with the source of air under pressure, a distributingchamber for distributing air under pressure carried by the cross frame,means providing communication between said tubular conduit and saiddistributor chamber, branch conduit means extending from saiddistributing chamber to all said pneumatically operated mechanisms,additional branch conduit means extended from said chamber to said twopneumatically actuated brake means, said control means controlling fuelfiow through all said branch conduitmeans and an additional controlmeans controlling the actuation of :saidfirst mentioned pneumaticallyoperated mechanism.

8 I 6. A log carriage as claimed in claim 5, in which said base framehas anroperators seat thereon rearwardly of said cross frame, saiddistributing chamber b ing mounted in front of said seat, the controlmeans common to the second pneumatically operated mechanism and itsassociated pneumatically actuated brake including a valve controllingfluid flow from the said .chamber to the pneumatically operatedmechanism and another valve controlling fluid flow from the chamber tothe pneumatically actuated brake mechanism, a single handle forcontrolling joint valves, the control means common to' the thirdpneumatically operated mechanism and its associated pneumaticallyactuated brake means jointly controlling fluid flow 7 from the chamberthrough the branch conduit means to the third mentioned pneumaticallyoperated mechanism and its associated brake mechanism, a handle for saidvalve and both said handles being mounted in front of the operatorsseat. 7

7. A log carriage as claimed in claim 1, and further including a tubularconduit carried by the base frame and adapted to be placed incommunication with the source of air under pressure, a distributingchamber for distributing air under pressure carried by the cross frame,means providing communication between said tubularconduit and saiddistributor'chamber, branch conduit means extending from saiddistributing chamber to all said pneumatically operated mechanisms,additionalbranch conduit means extended from said chamber to said twopneumatically actuated brake means, said control means controlling fluidflow through all said branch conduit means and an addi- J tional controlmeans controlling the actuation of said first mentioned pneumaticallyoperated mechanism, outlet conduit means mounted on said tubular conduitfor delivering air under pressure to a point of utilization and valvemeans for controlling fluid flow through said outlet con duit means. i

8. In a log carriage, a mobile base frame, a rod extend-1 ingtransversely of the base frame, a cross frame including a base portionfor supporting the cross frame for shift:

ing movement relative to the rod, a cylinder slidably em-, 7

bracing said rod and constituting the base portion of the cross frame, apiston means mounted on-said rod cen I trally thereof and within saidcylinder, log gripping claw Y unit means carried by said cross frame,conduit means communicating with opposite ends of the cylinder, controlmeans operably associated with said conduit means for controlling supplyand exhaust of fluid therethrough 1' 2 whereby said Cross frame and thussaid claw unit can be shifted laterally of the base frame in eitherdirection, fluid pressure actuated brake means including a brake platecarried by said cylinder, a brake cylinder carried by said base frame, abrake piston slidably mounted therein and normally engaging said brakeplate, conduit means communicating with said brake cylinder forsupplyingand exhausting fluid therefrom and said control means controlling fluid flow to said brake cylinder whereby said piston isnormally applied to said brake plate to fix the position of the cylinderand thus the claw unit and responsive to actuation of the control meansto shift the cylinder laterally of the base frame, said brake isdisengaged and upon cessation of shifting movement said brake isreengaged.

References Cited in the file of this patent UNITED STATES PATENTS3l7,25.6 Wilkin May 5, 1885 785,015 Masters Mar. 14, 1905 787,374 GrahamApr. 18, 1905 796,925 McDermott Aug. 8, 1905 1,503,280 Osbourne July 29,1924 1,588,364- Haskell June 8, 1926 2,154,038 Evrell Apr. 11, 19392,392,504 Readman et al. Jan. 8, 1946 2,596,475 Flygare V May 13, 19522,640,513 Watson etal. June 2, 19 53

